How do we come out to my extended family?

My wife (AMAB) and I just found out I’m pregnant! We’re SUPER excited but I realized today that it means that we need to tell my aunts/uncles/cousins/etc that she’s a trans woman. I would hate for her to get called “daddy” or something, as I know that would be pretty dysphoric for her. Both our parents and siblings know.

How have you told family members? I was thinking an email, because I don’t think I’m brave enough to tell my dad’s side of the family in person (they’re pretty conservative).